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Arny, earlier you had pointed to carl's website on the results of ABX tests. If you don't mind, I like to get your attention on this CD player test:

And the note under it. The testing found positive difference between them and that difference is explained (?) as the difference between 14 and "18" bit DACs in the respective players.

So this says that if I limit the CD resolution to 14 bits, the difference can be audible. Do you agree Arny?

Not the only difference. Probably not even a significant difference.

Furthermore, the reconstruction filter in the CDP 101 was a LCR filter and was therefore subject to sample variations. The actual frequency response of any particular CDP 101 sample is not totally certain.

My measurements show the CDP 101's Dynamic range at 91 dB and 1 KHz THD+N at 88 dB, so the CDP 101 was not much better than 14 bits, either.

As far as Hevi's DAC tests go, if I read his post correctly he's not claiming that the test was an airtight DBT or totally scientific. That puts its results into a questionable state, whether we like them or not.

Furthermore, the reconstruction filter in the CDP 101 was a LCR filter and was therefore subject to sample variations. The actual frequency response of any particular CDP 101 sample is not totally certain.

My measurements show the CDP 101's Dynamic range at 91 dB and 1 KHz THD+N at 88 dB, so the CDP 101 was not much better than 14 bits, either.

Thank you for the quick reply Arny. And the info on CDP 101. I am puzzled what that has to do with the units tested:

The Sony was not the CDP-101 but CDP-707 ESD. Do we have a set of excuses we can cite to dismiss these results too?

T
Do we have a set of excuses we can cite to dismiss these results too?

Given the absence of relevant technical tests then, it must all be a mystery. These tests were done by a different team in the Chicago area and they do not appear to be as rigorous overall as those done in SE michigan - AFAIK no corresponding technical tests were done. I'd ask Tom about it, but...

I looked up a CDP 707 service manual. Apparently a well built piece, way too bad that all we have to play on it is CDs.

It appears that the DAC chips were actually quad channel units with all of the sections hooked in parallel to get the 6 dB boost in dynamic range. And then we play these CDs on it that have only 70 dB or so DR because they are made in the real world, and play them in listening rooms that are probably even worse.

I have to disagree with John Atkinson regarding Kevin. I cannot speak for what he may or may not have done while at Snell, but I can state with complete confidence that Kevin is not an engineer and is not the Engineer for any Revel speaker, past or present. Of course he is involved with the product specifications and final voicing. Of course he is part of a team along with Mark, Mechanical engineers, program managers, product managers, etc. Of course Kevin's input is extremely important to the overall success of Revel speakers as well as Levinson product and a good many other things we do at Harman. It is still true that Mark is the sole system designer for Revel box speakers. Marketing, product management and the like is not engineering.

No problem with you disagreeing with me, Greg. Thanks for the clarification.

As far as Hevi's DAC tests go, if I read his post correctly he's not claiming that the test was an airtight DBT or totally scientific. That puts its results into a questionable state, whether we like them or not.

Well, as far as DBT goes, you stated this in another thread, where a *very* similar test methodology was critisized for not beeing DBT:

Quote:

Originally Posted by arnyk


The pregenerated script triggered by one-way voice commands from the listeners to a hidden operator probably satisfies the reasonable requirements for a DBT.

If "scientific" means publishing in a peer-reviewed paper, so no, I don't have any such amitions.

One conclusion that can be made is that under the circumstances, two of the participants detected differences in one DUT with statistical significance, so the hypothesis that "all DACs sound the same" was disproven in this setup.

Interesting test. Out of curiosity, I was wondering if the testers who couldn't really detect the differences between DACs thought they did, while the test was being run?

In other words, did they strongly believe they were making meaningful choices, or did it mostly sound the same to them, or differences were perhaps too subtle, or perhaps they couldn't remember them well enough to make the correct DUT identification?

There seems to be a lot of anxiety in the home theater threads, so I wouldn't say it is unique to the marble-encrusted-power-tower industry.

The home theater guys are typically wondering about the quality of their low-end components, there is a clear upgrade path with tangible rewards ahead of most of them. The high-end guys are hand-wringing over the quality of their high-end components, and there's often nowhere to go. It's a rare home theater guy who thinks blowing 60 grand on cables is going to somehow grant them access to Valhalla.

In this very thread, John Atkinson clearly stated that Stereophile does not test HDMI-compatible multi-channel receivers... because they are not 2-channel. IMO seems like an arbitrary distinction that (intentionally or not) erects a firewall against a whole class of devices that would threaten Stereophile's bread-and-butter "purist" 2-channel focus. Mind you, that's what the magazine's readers want—the exclusivity that comes with making anachronistic choices when it comes to both gear and music—so perhaps there is no point arguing. My first system (circa 1991) was based on JA's recommendations and it was memorably great. In fact, now that I've brought it up, it's story time...

I have a good friend who buys high-end gear. His original influence was me, and that Stereophile-rated system I bought back in 1991-1993. Today, he's $350,000-deep into Wilson and Krell gear. I'd say he spent 10X too much, relative to the performance of the system, thanks specifically to the sales tactics used by the high-end guys. Based on his taste in music, he'd be much better off with a maxed-out Seaton Sound system running off a good AVR, along with some room treatments. The hard part is how he can't even bear the thought that the high-end gear he owns doesn't represent the best performance his money can buy.

Quote:

Originally Posted by stereoeditor

Just to clarify, all my measurements of jitter rejection have been with S/PDIF, AES/EBU, and USB audio data connections. There hasn't been a call for me to measure HDMI connections because Stereophile only reviews 2-channel products; we leave AVR reviews to our stablemate Sound&Vision.

I own the same Audio Precision analyzer but something I learned from the late Raymond Cooke was that all test equipment can and will lie to you. Performing any test requires more than just pressing the "Start" button.

Arny, earlier you had pointed to carl's website on the results of ABX tests. If you don't mind, I like to get your attention on this CD player test:

And the note under it. The testing found positive difference between them and that difference is explained (?) as the difference between 14 and "18" bit DACs in the respective players.

So this says that if I limit the CD resolution to 14 bits, the difference can be audible. Do you agree Arny?

As a degreed EE, working off the premise there was indeed an audible difference, would you be confident in defending that conclusion as the primary cause or would other explanations take a more prominent role?

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House

As a degreed EE, working off the premise there was indeed an audible difference, would you be confident in defending that conclusion as the primary cause or would other explanations take a more prominent role?

Tests of music player hardware are exceptionally difficult to do properly. If one player drifts out of synch by even 10 mSec the players can be differentiated even if exactly identical hardware, because there will be a slight brief echo when you switch to the one that is running behind.

The Philips has a single dac chip and a less complicated analog filter section and a SAA7030 digital filter.

The sony has a 'staggered dac' approach with two chips making up the dac and a more complicated analog filter.
Also the Sony had a direct line output and a separate volume control output. 'Raising the question which of the output was used.'

I can imagine that a slight difference could be audible.
Depending on circuit tolerances the Sony model may have audible differences between different player samples due too possible 'lo bit dac' non linearity.

In this very thread, John Atkinson clearly stated that Stereophile does not test HDMI-compatible multi-channel receivers... because they are not 2-channel. IMO seems like an arbitrary distinction that (intentionally or not) erects a firewall against a whole class of devices that would threaten Stereophile's bread-and-butter "purist" 2-channel focus.

This isn't an arbitrary distinction. 80% of the magazine's readership have 2-channel systems, so the focus of the magazine's content addresses the interests of that majority. For the 20% who enjoy multichannel music reproduction, we have Kalman Rubinson's "Music in the Round" column. For video and home theater coverage, we left that to our stablemate Home Theater magazine, who in return left coverage of 2-channel audio to Stereophile. When we acquired Sound & Vision a year ago, the original plan was to merge it with Home Theater magazine. However, with the rapid commoditization of the home theater market, it was decided instead to roll Home Theater into Sound & Vision.

Quote:

Originally Posted by imagic

Mind you, that's what the magazine's readers want—the exclusivity that comes with making anachronistic choices when it comes to both gear and music—so perhaps there is no point arguing.

When I was around 10 years old, the same age that I became aware of the Periodic Table as mentioned in other postings in this thread, I read C.P. Snow's 1951 novel The Masters, The following statement has stuck in my memory ever since: "To be an influence in any society...one can be a little different, but only a little; a little above one's neighbours, but not too much."

If you go off on a tangent in which the readers have no interest, C.P. Snow warns that you would cease to have any influence. But if multichannel music replacement is to replace the 2-channel experience, you would see an increase in Stereophile's coverage of such hardware and recordings. But as all the signs are that such interest is static or even decreasing to judge by the products introduced at CES and other shows, I don't see that we will be expanding our coverage. And even Sound & Vision appears to be increasing its coverage of 2-channel components.

Quote:

Originally Posted by imagic

My first system (circa 1991) was based on JA's recommendations and it was memorably great.

Doesn't change the fact that the High End industry relies on it to sell their products.

There is no such "fact." Audio is a hobby. Pursuing the next piece of hardware to buy is not based on "anxiety." It is based on satisfying the hobby. You honestly think Jay Leno buys all of those expensive cars because someone is inducing anxiety in him?

As I said, the only anxiety that you can take to bank is the one we show in these posts over what the other guy is doing. That is not satisfying a hobby so if you want to wonder about something, that is where you want to focus.

As a degreed EE, working off the premise there was indeed an audible difference, would you be confident in defending that conclusion as the primary cause or would other explanations take a more prominent role?

I was not expressing my own opinion. Have you not read that website Chu? If you go there you see that I was making an observation based on the fact that if there is a difference, they often put in a footnote to explain why. Here is an example on capacitors: http://home.provide.net/~djcarlst/abx_caps.htm

The conditions of this test were extreme and do not represent normal operation. The experimenters could not confirm any audible difference between polypropelene and ceramic in many ABX tests under normal conditions. The condition that produced the above result of a difference was applying a 3.6 Watt heat source next to the capacitors. Even though the capacitor test circuit was not enclosed, with the added heat the ceramics lost capacitance to such an extent that the system's low frequence response was rolled off by 3 dB at 40 Hz.

So likewise under the CD player differences found, they say:

The Phillips CD-100 was serial number 345, the first CD player in the US and only 14-bit. The Sony CDP-707 uses 18-bit technology while the Panasonic SLS-295 uses 1-bit technology. These tests were published in PSACS Sound Bytes Vol. 7 No. 1 (Oct 96)

There would be no reason to comment that way unless they suspected the difference was due to 14 to "18" bit resolution differences.

You don't need an EE degree here. Just paying attention to details which is very important when it comes to interpreting testing results.

You honestly think Jay Leno buys all of those expensive cars because someone is inducing anxiety in him?

Poor analogy. There are real, noticeable differences between cars. The same sort of differences don't exist between amps, wires, ICs, CD players, etc. (unless one is talking about the "jewelry" aspects), not to mention the plethora of ridiculous tweaks that are solemnly paid attention to. The gullible are indeed made to feel anxious, the goal being to get them to shell out money to get the supposed "improvements" (something you've spent umpteen posts doing).

Poor analogy. There are real, noticeable differences between cars. The same sort of differences don't exist between amps, wires, ICs, CD players, etc. (unless one is talking about the "jewelry" aspects), not to mention the plethora of ridiculous tweaks that are solemnly paid attention to. The gullible are indeed made to feel anxious, the goal being to get them to shell out money to get the supposed "improvements" (something you've spent umpteen posts doing).

And, collecting cars like in his collections is also an investment. I am sure that is also part of Jay's motivation. Same could be applied to paintings.

I value improvements in these areas - soundstage and focus. Blacker background - my gear is dead silent, I suppose it can be applied to added distortions/noise while playing.

When they aren't right - well, there is something wrong, be it equipment, or speaker positioning, or room problems, or the recording itself.

It's certainly a subjective thing. I don't know how you could conveniently measure your perception of the spatial attributes (illusion) of an audio presentation. I suppose some people are unable to perceive it at all. And qualitative, you simply may not care.

I first experienced stereo in 1959 when Dad and I completed the construction of the Eico integrated stereo and we sat between the Pilot speakers and were transfixed by the illusion.

I was not expressing my own opinion. Have you not read that website Chu? If you go there you see that I was making an observation based on the fact that if there is a difference, they often put in a footnote to explain why.

Yes, there's a footnote for the CDPs but I don't take that to mean that tiny blurb is their position as to why there was an audible difference. That's something I would place elsewhere with a bit more justification. They may have well listed the weights, colors or whatever.

The conditions of this test were extreme and do not represent normal operation. The experimenters could not confirm any audible difference between polypropelene and ceramic in many ABX tests under normal conditions. The condition that produced the above result of a difference was applying a 3.6 Watt heat source next to the capacitors. Even though the capacitor test circuit was not enclosed, with the added heat the ceramics lost capacitance to such an extent that the system's low frequence response was rolled off by 3 dB at 40 Hz.

The capacitors are somewhat less complicated than a CDP.

Quote:

So likewise under the CD player differences found, they say:

The Phillips CD-100 was serial number 345, the first CD player in the US and only 14-bit. The Sony CDP-707 uses 18-bit technology while the Panasonic SLS-295 uses 1-bit technology. These tests were published in PSACS Sound Bytes Vol. 7 No. 1 (Oct 96)

There would be no reason to comment that way unless they suspected the difference was due to 14 to "18" bit resolution differences.

IMO you're overreaching

Quote:

You don't need an EE degree here. Just paying attention to details which is very important when it comes to interpreting testing results.

These are exceedingly brief and terse results. If you want to know the reason why they footnoted as they did then efforts should be made to contact them and ask for an explanation.

But let's run with it. You asked Arny if the difference in bits was an adequate reason to explain the audible differences. In your professional opinion would you concur with that?

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House